In one of the operations to recycle glass, the glass is crushed and passed through several stages one of which involves the use of vacuum means to separate low density solids, such as plastic, paper, foil, cork and wood, from the crushed glass. This creates a problem in that the airflow containing the low density products will,plug baghouses, dust collectors or other similar apparatuses needed to process the airflow before passing it to the atmosphere. In some instances, the airflow is passed through cyclone separators which are expensive and somewhat inefficient for this type of service.